G-SYNC 101: Control Panel


G-SYNC Module

The G-SYNC module is a small chip that replaces the display’s standard internal scaler, and contains enough onboard memory to hold and process a single frame at a time.

The module exploits the vertical blanking interval (the span between the previous and next frame scan) to manipulate the display’s internal timings; performing G2G (gray to gray) overdrive calculations to prevent ghosting, and synchronizing the display’s refresh rate to the GPU’s render rate to eliminate tearing, along with the delayed frame delivery and adjoining stutter caused by traditional syncing methods.

G-SYNC Demo

The below Blur Busters Test UFO motion test pattern uses motion interpolation techniques to simulate the seamless framerate transitions G-SYNC provides within the refresh rate, when directly compared to standalone V-SYNC.

G-SYNC Activation

“Enable for full screen mode” (exclusive fullscreen functionality only) will automatically engage when a supported display is connected to the GPU. If G-SYNC behavior is suspect or non-functioning, untick the “Enable G-SYNC, G-SYNC Compatible” box, apply, re-tick, and apply.

Blur Buster's G-SYNC 101: Control Panel

G-SYNC Windowed Mode

“Enable for windowed and full screen mode” allows G-SYNC support for windowed and borderless windowed mode. This option was introduced in a 2015 driver update, and by manipulating the DWM (Desktop Windows Manager) framebuffer, enables G-SYNC’s VRR (variable refresh rate) to synchronize to the focused window’s render rate; unfocused windows remain at the desktop’s fixed refresh rate until focused on.

G-SYNC only functions on one window at a time, and thus any unfocused window that contains moving content will appear to stutter or slow down, a reason why a variety of non-gaming applications (popular web browsers among them) include predefined Nvidia profiles that disable G-SYNC support.

Note: this setting may require a game or system restart after application; the “G-SYNC Indicator” (Nvidia Control Panel > Display > G-SYNC Indicator) can be enabled to verify it is working as intended.

G-SYNC Preferred Refresh Rate

“Highest available” automatically engages when G-SYNC is enabled, and overrides the in-game refresh rate selector (if present), defaulting to the highest supported refresh rate of the display. This is useful for games that don’t include a selector, and ensures the display’s native refresh rate is utilized.

“Application-controlled” adheres to the desktop’s current refresh rate, or defers control to games that contain a refresh rate selector.

Note: this setting only applies to games being run in exclusive fullscreen mode. For games being run in borderless or windowed mode, the desktop dictates the refresh rate.

G-SYNC & V-SYNC

G-SYNC (GPU Synchronization) works on the same principle as double buffer V-SYNC; buffer A begins to render frame A, and upon completion, scans it to the display. Meanwhile, as buffer A finishes scanning its first frame, buffer B begins to render frame B, and upon completion, scans it to the display, repeat.

The primary difference between G-SYNC and V-SYNC is the method in which rendered frames are synchronized. With V-SYNC, the GPU’s render rate is synchronized to the fixed refresh rate of the display. With G-SYNC, the display’s VRR (variable refresh rate) is synchronized to the GPU’s render rate.

Upon its release, G-SYNC’s ability to fall back on fixed refresh rate V-SYNC behavior when exceeding the maximum refresh rate of the display was built-in and non-optional. A 2015 driver update later exposed the option.

This update led to recurring confusion, creating a misconception that G-SYNC and V-SYNC are entirely separate options. However, with G-SYNC enabled, the “Vertical sync” option in the control panel no longer acts as V-SYNC, and actually dictates whether, one, the G-SYNC module compensates for frametime variances output by the system (which prevents tearing at all times. G-SYNC + V-SYNC “Off” disables this behavior; see G-SYNC 101: Range), and two, whether G-SYNC falls back on fixed refresh rate V-SYNC behavior; if V-SYNC is “On,” G-SYNC will revert to V-SYNC behavior above its range, if V-SYNC is “Off,” G-SYNC will disable above its range, and tearing will begin display wide.

Within its range, G-SYNC is the only syncing method active, no matter the V-SYNC “On” or “Off” setting.

Currently, when G-SYNC is enabled, the control panel’s “Vertical sync” entry is automatically engaged to “Use the 3D application setting,” which defers V-SYNC fallback behavior and frametime compensation control to the in-game V-SYNC option. This can be manually overridden by changing the “Vertical sync” entry in the control panel to “Off,” “On,” or “Fast.”



1149 Comments For “G-SYNC 101”

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AlianosFN
Member
AlianosFN

Hi, I have a question.

I play Fortnite competitively on a 165 Hz 1440p monitor with a GTX 1070 Ti using pretty much all the settings you recommended in this thread (gsync ON, vsync ON, game on fullscreen, fps limited in game files to 162, and finally low latency mode ON).

Now since the nvidia driver update from today got released the new nvidia Reflex Low Latency setting was added to the game. With the setting come 3 options: OFF, ON or ON + BOOST. A thing i noticed when i turned it to either ON or ON + BOOST was that instead of my fps cap being 162, my fps got capped at 158 (so 4 frames lower than the limit i set myself).

This raised a question;
Does turning the setting ON (or ON + BOOST) impact the way gsync works (also in combination with the other recommended settings in this thread)?
If so, what would you recommend me to do? Should i keep the nvidia reflex setting off? Or should i keep it on (since according to nvidia it reduces system delay) and change my fps cap to make up for the 4 frames i lost?

Ultimately i think my question is; how does the nvidia reflex low latency setting fit in the picture with gsync and the recommended settings in this thread?

Thanks in advance for taking the time to read/answer to my questions!

tomato884
Member
tomato884

does this apply to the new 30xx series with all the new reflex technology?

JediBrysen
Member
JediBrysen

should competitive players for any game but for my situation fortnite use this? I really just want low input delay while it being smooth

ankurszn
Member
ankurszn

i have the same question

Avean
Member
Avean

Could LLM = On with G-Sync cause frametime spikes in cases where the game uses its own frame queue? Cause in the end of the article you say you recommend testing this on per-game basis to see if worse or not. And if at best youre improving latency by 1 frame, its kinda best to leave it off i feel? Unless you want to fire up RivaTuner and monitor each game to see if improvements. But really the biggest impact is more framerate than whatever setting your LLM is at, feel people are kinda hung up on this setting 🙂

Glarbstintenford
Member
Glarbstintenford

Amazing guide and information, thank you so much!

I have a questions or two, sorry this ends up being so long but I wanted to also share the information I found and make it as clear as possible:

1 – Does the use of the smoothframes feature found in Unreal Engine 4 have any effect? I’m not sure how smoothframes & in game Vsync relate to each other with or without G-Sync and thought you could shed some light.

The game I play is online multiplayer only, and their servers currently run 30Hz tickrate, which in the near future will be increasing to 60Hz tickrate.

It has smoothframes and vsync enabled by default, using the default 22-62FPS range for smoothframes, with no in-game option to disable either or set an FPS limit. It also has what I am assuming is an in-game FPS limiter that you can manually adjust via editing the ini files. This line is FrameRateLimit= and the default is =0.000000.

Also just so you know this game has no in-game settings other than a resolution scale slider that’s it, and only runs in borderless fullscreen.

However you can edit GameUserSettings.ini and disable/enable vsync & smoothframes.

Now with or without G-Sync enabled I have discovered the following:

– If I use the games default settings of vsync and smoothframes enabled and FrameRateLimit=0 I am limited to 62FPS regardless of desktop refresh rate provided that my desktop refresh rate is higher than 63Hz **However if I set FrameRateLimit to any number up to and including 120 then my FPS limited to that number unless my desktop refreshrate is lower than the value set in FrameRateLimit= in which case it is limited to desktop refresh rate.

– If I disable in-game vsync and leave smoothframes enabled I am still limited to 62FPS regardless of desktop refresh rate if FrameRateLimit=0

– If I keep in-game vsync enabled and only disable smoothframes my FPS is capped to desktop refresh rate but only to 120 any refresh rate above that I’m still limited to 120FPS. Also worth noting this is when leaving FrameLimit=0.000000

– If I disable in-game vsync & disable smoothframes and FrameRateLimit=0 then my FPS is uncapped.

Wonderinig if smoothframes should be enabled or disabled, as well as if using FrameRateLimit should be used and am curious what your thoughts are about it all.

Thank you! 🙂

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